The present invention is directed generally to novel systems and methods for performing sputter deposition, and to optical devices manufactured using such systems and methods.
It is believed that in vapor deposition systems such as ion beam sputtering, magnetron sputtering, diode sputtering, thermal evaporation, electron beam evaporation, pulse laser vaporization and cathodic arc vaporization, atoms or molecules ejected from a target material are directed toward a substrate where they condense to form a film. In most cases, the deposited film shows variation in thickness across the wafer that the user would like to eliminate (for uniform deposition) or control (thickness gradient) to meet the needs of a particular application. It would be beneficial to provide a system that improves control of the deposition thickness distribution over a wafer and from wafer-to-wafer during manufacturing runs.
The present invention is directed to a system and method for controlling a deposition thickness distribution over a substrate. The system comprises a motor that rotates the substrate and at least one sensor that senses the deposition thickness of the substrate at two or more radii on the substrate. An actuator varies a shadow of a mask disposed over a target used to sputter material on the substrate. An ion source generates an ion beam that is directed toward the target. The mask is positioned between the ion source and the target, and selectively blocks ion current from the ion source from reaching the target. A process controller is coupled to the deposition thickness sensor and the actuator. In response to the sensed deposition thickness, the process controller varies the shadow of the mask with respect to the target to control the deposition thickness distribution over the substrate.
The invention also includes an optical filter that is created by the disclosed systems and methods. The optical filter comprises a substrate, and material disposed on the substrate using the disclosed systems and methods.